firefly_types/
encode.rs

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use alloc::vec::Vec;

pub trait Encode<'a>
where
    Self: core::marker::Sized + serde::Deserialize<'a> + serde::Serialize,
{
    /// Load object from bytes generated by [`Encode::encode`].
    ///
    /// # Errors
    ///
    /// May return an error if the buffer does not contain a valid object.
    fn decode(s: &'a [u8]) -> Result<Self, postcard::Error> {
        postcard::from_bytes(s)
    }

    /// Encode the object as a Vec.
    ///
    /// If you want to avoid dynamic allocations, use [`Encode::encode_buf`] instead.
    ///
    /// # Errors
    ///
    /// In theory, may return an error if any of the types cannot be serialized by
    /// postcard. However, all the types defined in this crate are very simple,
    /// so it shouldn't happen.
    fn encode_vec(&self) -> Result<Vec<u8>, postcard::Error> {
        postcard::to_allocvec(self)
    }

    /// Encode the object using the buffer.
    ///
    /// The buffer is required to avoid allocations on the crate side.
    /// Use [`Encode::size`] to calculate the required buffer size.
    ///
    /// # Errors
    ///
    /// May return an error if the buffer is not big enough.
    fn encode_buf<'b>(&self, buf: &'b mut [u8]) -> Result<&'b mut [u8], postcard::Error> {
        postcard::to_slice(self, buf)
    }

    /// Calculate the buffer size required to encode the object.
    #[must_use]
    #[allow(clippy::missing_panics_doc)]
    fn size(&self) -> usize {
        let flavor = postcard::ser_flavors::Size::default();
        postcard::serialize_with_flavor(self, flavor).unwrap()
    }
}